It was a mixed day for the airline industry as shares in Ryanair and the owner of rival Jet2.com took off in opposite directions.

Dart Group, which owns Jet2.com, dived 12 per cent after it set out just how much it expects last week’s landmark ruling in the Supreme Court will cost.

Judges rejected an appeal from the company over a symbolic compensation case that could herald a flood of claims from passengers who have endured long delays.

Dart said it will set aside £17million this year to cover any historical claims arising from the ruling.

‘Going forward, the board estimates that the legislation may cost the group a further £3million-£5million per annum,’ it said in a statement to the stock exchange.

Shares fell 31.5p to 229.5p.

The case related to Ronald Huzar, a 58-year-old from Stockport who was refused compensation by Jet2.com following a 27-hour delay when travelling with his wife and granddaughter from Malaga to Manchester in 2011.

Stockport County Court and then the Court of Appeal both ruled in his favour.

Jet2.Com appealed against this ruling – this time to the Supreme Court.

The airline argued that in certain circumstances unexpected technical problems that caused delays or cancellations were outside its control.

As a result, they would be considered an ‘extraordinary circumstance’ under European laws that dictate compensation must only be paid if the delays or cancellations are within the airline’s control.

But last week judges threw out Jet2.com’s request to appeal – handing Huzar a total of £940 in compensation.

Ryanair fared far better yesterday after it reported a 32pc rise in half-year profits to £621million and said it now expects its full-year haul to be between £586million and £602million. Shares rose 7.32 per cent or 56 cents to €8.15.

The bullish report boosted share prices across the sector with easyJet up 40p to 1540p and British Airways owner International Consolidated Airlines Group up 5.1p to 414.3p.

The FTSE 100 index dipped 58.5 points to 6487.97 on a subdued start to the week in London while the FTSE 250 was 48.22 points lower at 15453.15. In New York, the Dow Jones Industrial Average closed down 24.28 points at 17,366.24. It has been a terrible year for shareholders in Ocado and AO World but both stocks raced higher yesterday.

Ocado, which peaked at 617p in February but fell as low as 220p last month, jumped more than 10 per cent or 25.6p to 274.3p. AO World, which floated at 285p in February and quickly rose above 400p before sinking to 154p last month, added nearly 9 per cent or 14.3p to 180.2p.

‘It is interesting to see many of the online retailing stocks jumping in unison in the London market,’ said Louis Coke at Charles Stanley. ‘This follows quite a re-rating for the sector recently.

‘As technology becomes cheaper and more readily available and with mobile becoming a real commercial force, I would expect to see this trend continue.

‘That said, there are bound to be some bumps along the way. These stocks can easily get up to very expensive ratings, which can lead to quite a volatile share price as the companies have to keep beating ever-increasing financial forecasts.’

Back in the top flight, blue chip utility stocks came under pressure after analysts at Investec started their coverage of United Utilities and Severn Trent with a ‘sell’ rating. British Gas owner Centrica fell 7p to 295.5p and rival SSE was down 32p to 1567p while United Utilities shed 17.5p to 837p and Severn Trent lost 32p to 1964p.

‘I’m still a fan of the utility stocks, due to their chunky dividend yields, but I wouldn’t buy them at current levels,’ said Richard Griffiths, associate director at Berkeley Futures.

Shares in Aveva fell another 42p to 1494p yesterday having lost nearly a third of their value since releasing a profits warning in September.

Goldman Sachs downgraded its rating on the engineering software provider to ‘sell’ and cuts its target price from 1950p to 1420p.

It was another tough session for investors in Super Dry owner SuperGroup following last week’s profits warning. Shares fell 26.5p to 803.5p. Not an easy start for new chief executive Euan Sutherland, the former boss of the Co-op.

- World gold prices fell to their lowest level for more than four years yesterday, dipping below $1,170 an ounce. Bullion, which is seen as a safe bet during times of trouble, was trading at close to $1,900 in 2011 but has suffered a dramatic sell-off since then with many analysts expecting it to drop below $1,000. ‘A strong dollar and a healthy financial system has removed many of the traditional reasons to bank on the metal,’ said David Madden, an analyst at IG.